The principal purposes of using a subframe are, to spread high chassis loads over a wide area of relatively thin sheet metal of a monocoque body shell, and to isolate vibration and harshness from the rest of the body. For example, in an automobile with its powertrain contained in a subframe, forces generated by the engine and transmission can be damped enough that they will not disturb passengers. As a natural development from a car with a full chassis, separate front and rear subframes are used in modern vehicles to reduce the overall weight and cost. In addition a subframe yields benefits to production in that subassemblies can be made which can be introduced to the main bodyshell when required on an automated line.